Burkhardt, S., and J. T. Lehman, 1994. Prey Consumption and Predatory Effects of an Invertebrate Predator (Bythotrephes: Cladocera, Cercopagidae) Based on Phosphorus Budgets. University of Michigan

Prey Consumption and Predatory Effects of an Invertebrate Predator (Bythotrephes: Cladocera, Cercopagidae) Based on Phosphorus Budgets

Abstract
Phosphorus excretion rates, ingestion efficiency, and P content of Bythotrephes at different develop mental stages are used to estimate predation rates indirectly from metabolic needs. A growth model is developed to predict P content and weight of this invertebrate planktivore throughout its life. P consumption required to complete one parthenogenic life cycle of the predator is estimated from metabolic rates and weight measurements of individual instars. Based on P requirements and prey stoichiometry, empirical ingestion efficiency of 59%, and assimilation efficiency of 85%, each Bythotrephes consumes the equivalent of 14 Daphnia per day on average and can inflict mortality equal or greater in magnitude to Daphnia recruitment rates during midsummer in offshore waters of Lake Michigan, particularly when predator population abundance exceeds 400 individuals m- ² .

Entire Paper
Contact: Steffen Burkhardt, Dept. of Biology, University of Michigan, Ann Arbor, MI 48109
Keywords: Bythotrephes, Ecological_interactions, Predators, Environmental_impacts
Product Type: Research, Impact
User Type: Resource_management